空大的希维尔 空大的希维尔
欢迎访问空大联盟吧≧▽≦
关注数: 85 粉丝数: 86 发帖数: 6,135 关注贴吧数: 6
【紧急求助】哪位英语好的进来帮忙翻译,整理语句顺序就行 The Cu/ZnO catalyst (Cu/ZnO = 1:1, molar ratio) for the hydrogenationof methyl acetate was prepared by a conventional co-precipitation method. 7.5gof Cu (NO3) 2`3H20 and 9.3g of Zn (NO3)2`6H2O were dissolved into 300 mLdiluted water and then the obtained mixture solution and 300 mL aqueous Na2CO3solution were mixed synchronously keeping a constant pH value of 8.5 at 333Kwith continuous stirring to from a blue color slurry. The slurry was then agedovernight. The precipitate was filtrated and washed with deionized water for 4times. The obtained solid was dried at 393K for 12h and was then calcined at623K for 1h in air followed by being pelletized and screened to the size of0.43 to 0.85mm. Thereafter the obtained precursor was reduced by a flow of purehydrogen at 573K for 10h and then was passivated by 1% oxygen diluted withnitrogen at room temperature for 6h. The Cu/ZnO catalyst(催化剂) (Cu/ZnO = 1:1, molar ratio(摩尔比率)) for the hydrogenation(加氢催化剂) of methyl acetate(乙酸甲酯) was prepared by a conventional(传统的) co-precipitation(共沉淀) method. 7.5gof Cu (NO3) 2`3H20 and 9.3g of Zn (NO3)2`6H2O were dissolved(溶解) into 300 mL diluted(稀释) water and then the obtained mixture solution(溶液) and 300 mL aqueous(蒸馏水) Na2CO3 solution were mixed synchronously(同时) keeping a constant(稳定的) pH value of 8.5 at 333K with continuous stirring(搅拌) to from a blue color slurry(淤浆). The slurry was then aged overnight. The precipitate(沉淀) was filtrated(过滤) and washed with deionized water(去离子水) for 4times. The obtained solid(固体的) was dried at 393K for 12h and was then calcined(焙烧) at 623K for 1h in air followed by being pelletized(使…成为颗粒) and screened(过筛) to the size of0.43 to 0.85mm. Thereafter the obtained precursor(前驱体) was reduced(还原) by a flow of pure(保持) hydrogen(氢气) at 573K for 10h and then was passivated(钝化) by 1% oxygen(氧气) diluted(稀释) with nitrogen(氮气) at room temperature for 6h. The total fossil energy expended to pro duce 1 liter of ethanol fromcorn is 10200 kcal, but note that 1 liter of ethanol has an energy value ofonly 5130 kcal. Thus, there is an energy imbalance causing a net energy loss.Approximately 53% of the total cost of producing ethanol in a large, modern plant is for the corn raw material. The total energy inputs for producing ethanol using corn can be partially offset when the dried distillers grain produced is fed to livestock. Although the feed value of the dried distillers grain reduces the total energy inputs by 8% to 24%, the energy budget remains negative. The total fossil(化石) energy expended(膨胀) to produce 1 liter(公升) of ethanol(乙醇) from corn(谷物) is 10200 kcal, but note(注意) that 1 liter of ethanol has an energy value of only 5130 kcal. Thus, there is an energy imbalance(不平衡) causing a net energy loss.Approximately(大约) 53% of the total cost of producing ethanol in a large, modern plant is for the corn raw(生的) material(材料). The total energy inputs for producing ethanol using corn can be partially(部分的) offset(抵消) when the dried distillers(蒸发器) grain(谷物) produced is fed to livestock(牲畜). Although the feed value of the dried distillers grain reduces the total energy inputs by 8% to 24%, the energy budget(预算) remains negative. Although ethanol has been advertised as reducing air pollution when mixed with gasoline or burned as the only fuel, there is no reduction when the entire production system is considered. Ethanol does release less carbon monoxide and sulfur oxides than gasoline and diesel fuels. However, nitrogen oxides, formaldehydes, other aldehydes (all serious air pollutants) are associated with the burning of ethanol as fuel mixture with or fuel mixturewith or without gasoline. Also, the production and use of ethanol fuelcontribute to the increase in atmospheric carbon dioxide and to global warming,because twice as much fossil energy is burned in ethanol production than isproduced as ethanol. Although ethanol has been advertised as reducing air pollution when mixed with gasoline or burned as the only fuel, there is no reduction when the entire(全部的) production system is considered. Ethanol does release(释放) less carbon monoxide(一氧化碳) and sulfur oxides(二氧化硫) than gasoline and diesel fuels. However, nitrogen oxides(氮氧化合物), formaldehydes(甲醛), other aldehydes(醛类) (all serious air pollutants(污染物)) are associated(合伙) with the burning of ethanol as fuel mixture with or fuel mixturewith or without gasoline. Also, the production and use of ethanol fuelcontribute to the increase in atmospheric carbon dioxide and to global warming,because twice as much fossil energy is burned in ethanol production than isproduced as ethanol. Water-use in agriculture has marked effects on the environment, notall of them adverse. Reservoirs created for irrigation can provide fresh waterfor birds and other fauna; terraces for growing rice can help slow down run-offand reduce erosion; water-management for agricultural purpose can replenish thewater-table and stabilize river levels. The diversion of water for agriculture has often causedenvironmental problems and degraded natural resources. The steady flows thatdams cause alter the seasonal cycles of aquatic and riparian plants andanimals. Reduced stream flows and excessive use of groundwater aquifers lead tohigher concentrations of pollutants. Excessive extraction can lowerwater-tables, leading, in some cases, to ground subsidence and, in some coastalareas, to salt-water intrusion. And because irrigation water almost alwayscontains much higher concentrations of dissolved salts than rainwater, itsdischarge often raises the proportion of salts in the bodies of water intowhich it flows.
首页 1 2 3 4 下一页